“Now the serpent was the shrewdest of all the creatures the LORD God had made.” (Genesis 3:1)
It is common to believe a fallen angel caused the temptation that led to the fall of mankind. This is not true; the serpent caused the temptation that led to the fall of mankind and our eviction from the Garden of Eden.
If you read all of Genesis 3, you will find no mention of the Devil, Satan, demons, Lucifer, or a fallen angel. When judgment was given after the fall; Eve was sentenced (verse 16), Adam was sentenced (verses 17-19), and the serpent was sentenced (verse 14). There was no sentence for the Devil as he was not there.
Some people say the Devil was the serpent, but the Devil does not crawl on his belly the way the serpent must. The serpent was told, “You will grovel in the dust as long as you live, crawling along on your belly.” (Genesis 3:14) This is not how the Devil walks, thus the serpent is not the Devil.
Others say the Devil made the serpent talk. This cannot be so as 2 Corinthians 11:3 says, “Eve was deceived by the serpent.” The Swedish Bible is even clearer, saying, “The serpent deceived Eve with his own subtlety.”
We see from all this that the serpent deceived Eve all by himself.
Quotations from the NLT Bible and the Swedish Bible.